Razor stropping mechanism



D. G. MCPEAKV l RAZOR STROPPING MECHANISM Sept. 6, 1938.

' Filed March 27. 1936 2 sheets-sheer 1 INVENTOR Nwm ATTORN EY Sept 6, 1938. l D, G, MC|= EAKV 2,129,378

RAZOR STROPPING MECHANISM Filed March 27. 1956 2 Sheets-Sheet 2 Fgml L INVENTOR ATTORNEY Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE l Application March 27,

4 Claims.

My invention, relates to improvements in razor stropping mechanisms, with particular reference to that class of mechanisms which are employed for stropping safety razor blades.

Objects of my invention are to provide an improved plate holding carriage and improved means for guiding the carriage and tensioning it to facilitate blade reversal preparatory to a reversal in the direction of carriage movement.

In the drawings:

Figure 1 is a plan view of a razor stropping mechanism embodying my invention.

Figure 2 is a side elevation of the same.

Figure 3 is a sectional view drawn to line 3-3 of Figure l.

Figure 4 is a sectional View drawn to line 4--4 of Figure 2.

Figure 5 is a side elevation of the carriage with the plate holder in a vertical position midway between its two working positions.

Figure 6 is a plan view of the carriage as it appears when detached.

Like parts are identified by the same reference `characters throughout the several views.

A strop holder plate Il) formed with a handle II at one end has its upper side surface provided with obliquely disposed strips I2 of stropping material, preferably leather, cemented or otherwise adhesively secured to the holder plate Il). Par- 36 allel to the upper surface of the plate IIJ it is provided with an elongated guideway l5 which may be formed by cutting an open ended slot in plate ID and closing the open end by means of a filler block I6 after the carriage has been assembled as 35- hereinafter explained. This filler block I6 may be secured in position by means of screws Il, whereupon the block will serve as a stop for the carriage at the. outer end of its stroke.

Above and below the slot or guideway I5 the 40 plate I0 is channeled along one side as indicated at I8 and I9, to provide a guide or runway for a tensioning plate 20 associated with the carriage now to be described.

'I'he carriage comprises side walls 25 and 25 45 connected by cross rods 2l. These cross rods intermediate of their ends are of a diameter substantially equal to the vertical dimensions of the slo-t I5 in which they have a sliding fit. They have end portions of reduced diameter which extend through holes in the carriage wall and are provided with heads 28,` Their other ends are similarly reduced to provide neck portions of greater length, whereby they may be passed through slots 29 in a rack carrying slide 35 and 554 through holes in the carriage wall 25.

TST

1936, Serial N0. 71,144

The slots 29 permit an independent movement of the rack carrying slide 30 without actuating the carriage, the latter being normally held in a stationary position by the friction of the tension plate 20 upon the inner walls of the channels or rabbets I8 and I9 under tension imposed by coiled springs 33 which connect the tension plate 20 with the wall 25 of the carriage. This wall 25 also bears frictionally upon the adjacent edge of the holder plate I0.

An operating handle or knob 35 has a shank 36 which extends through a slot 31 in the carriage wall 26 and through a hole in the slide 3l] to which it is secured by a screw 38 threaded into the end of the shank 36, whereby the slide 30 may be manually actuated by means of the knob 35.

The slide 30 is provided with a rack bar 40 having upwardly projecting teeth 4I in mesh with the teeth of a pinion 42 carried by an oscillatory shaft 43 to which a razor blade holder is secured, this holder having convergent side plates 44 and 45 adapted to clampingly engage a razor blade as indicated at a in Fig. 5. The plates 44 and 45 are xedly secured at their respective ends to shaft 43 by means of end disks 4l through which reduced end portions of shaft 43 are passed. These reduced end portions of shaft 43 are journaled in the upwardly extending side walls 25 and 26 of the carriage. The portions of the shaft which pass through the disks 41 may be squared or anchored to the disks 4l in any suitable manner, and the blade holder members 44 and 45 are rigidly secured to these disks 41.

In operation the knob 35 is reciprocated to first move the slide 30 until one end of each slot 29 engages the associated carriage shaft 2l, whereupon continued motion will be transmitted to the carriage. The initial movement of slide 30 will be transmitted through the rack 4I and pinion 42 to adjust the blade in proper stropping position. When the motion is transmitted to the carriage the blade will be drawn across the stropping bands I 2, preferably until the advancing carriage ross rod 2l strikes the end block I6 when moving in one direction, or the inner end of the slot I5 when moving in the other direction.

In each instance, upon reversal of the direction of movement, the slides 3i! will be initially moved along the wall 26 of the carriage until the cross rods 2l engage the opposite ends of their associated slots. During this initial movement of the slide 30 the carriage will be held to the holder plate I0 by the tension bar 20 which, however, will not develop sufficient friction to prevent the carriage from being manually moved without the strop supports canV serve as guides.

undue exertion after the slide has completed its independent movement. It will, of course, be understood that during this independent movement the position of the razor blade will have been reversed by means of the rack and pinion.

I am aware of the fact that stropping mechanisms have heretofore been constructed with blade supporting carriages and with rack and pinion means for reversing the position of the blade. So far as I am aware, such mechanisms have not been adapted to reverse and` move the blade with the desired smoothness and uniformity of pressure upon the stropping material. essential to maximum efficiency that the carriage and the slide should be guided in a true lineal stroke at substantially uniform speed throughout the length of stroke and without varying resistance such as occurs if lateral or vertical or torsional movements are permitted.

By providing a slide 3B of greater length than the carriageI and adapted to t against the side margin of the holding plate I0, and by providing cross shafts or rods 2l which have a sliding fit in theslot l5 to prevent vertical movement, and by providing the tension bar 26 which is held by the springs 33 in sliding t relation to the runners I8 and I9, I obtain the required smoothness and freedom from vibratory shock while permitting ease of manipulation by means of the laterally projecting knob 35. Also, my improved razor strop can be so inexpensively constructed as to make it available to persons of small means.

I am aware of the fact that attempts have heretofore been made to provide commercially successful strops, the frames of which have channel bar sides arranged with the channels facing inwardly, and serving as guides for a set of slides subject to resilient outward pressure between the upper and lower flanges of the chanplates, reversingV mechanism, and the slides must Y operate between the strop and the channelled sides of the frame, and neither the strop nor Access to the guiding and controlling mechanism is not possible without taking the frame apart and disturbing the alignments. Also, these guiding and controlling members are invisible during operai; tion, and if any of the parts stick, catch or bind,

the cause cannot be ascertained by inspection during operation, whereas in my improved stropping mechanism all of the parts are visible in operation andthe strop holder can be laid flat fupon the table and held rigidly thereon while manipulating the laterally projecting handle without interference with visibility. Also, both the upper and the lower walls of the strop holder plate may be formed of wood and a rigidly supported strop applied to the upper surface, and because of this rigidity, accurate positioning and alignment of the working parts is easily obtained.

It will be observed that the strips of stropping material extend across the holder at approximately a 45 degree angle to the line of movement of the carriage and blade support. Therefore the blade is substantially at all times inl contact with twoof the strips, thereby avoiding any tendency toward an axial tilting of the blade due to a lack 'of' support on both sides of its transverse center line.

I claim'i 1. In a stropping mechanism of the described class, the combination with a rigid strop holder having a stropping surface of a carriage adapted It is for sliding movement along the strop holder and having spaced side walls rigidly connected by cross rods in a common plane, blade holding and reversing mechanism associated with one of the side walls, and a tension plate adjacent said side wall and resiliently connected with the opposite side wall by tension springs located between said cross rods and substantially in the plane thereof, whereby said carriage may be operated along the sides of the rigid strop holder with the cross rods extending between upper and lower portions of the holder to allow the holder to rest upon a table while the carriage is being reciprocated.

2. In a mechanism of the described class, a rigid strop holder surfaced with stropping material on one side and having a longitudinally extending slot parallel with the stropping surface, said strop holder being channelled along one margin to form a laterally facing guideway, in combination with a razor blade carriage having cross rods in sliding t relation to said slot, a

blade reversing slide mounted for limited movement along one side of the carriage and provided with a laterally projecting actuating knob, said carriage having a tensioning plate in sliding lit relation to the guideway, and tension springs extending through said slot and connecting the tensioning plate with the opposite side wall of the carriage to resiliently clamp the carriage to the sides of the strop holder, said springs being adapted to impart a greater resistance to the movement of the carriage than that of the blade adjusting slide in its movement relatively to the carriage.

3. The combination with a horizontally slotted rigid stropping bar having a stropping upper surface, of a rigid blade carrier having side plates connected with each other by spaced cross bolts extending through the slot in said bar, said bolts being adapted to also support the carrier from the l e bar, a rack carrying slide plate associated with the inner .face of one of the carrier side plates for independent movement limited by said cross bolts, a tension plate between the slide plate and said bar and connected with the opposing side i plate by tension springs extending through the slot in said bar, Vsaid bar having a longitudinal guide groove in one margin within which the tension plate may operate, and a blade holder supported by the carrier and having a blade reversing pinion in engagement with the slide plate rack.

4. The combination with a horizontally slotted rigid stropping bar having a stropping upper surface, of a rigid blade carrier having side plates connected with each other by spaced cross bolts extending through the slot in said bar, said bolts being adapted to also support the carrier from the bar, a rack carrying slide plate associated with the inner face of one of the carrier side plates for independent movement limited by said cross bolts, a tension plate between the slide plate and said bar and connected with the opposing side plate by tension springs extending through the slot in said bar, said bar having a longitudinal guide groove in one margin within which the tension plate may operate, and a blade holder supported by the carrier and having a blade reversing pinion in engagement with the slide plate rack, saidslide plate being provided with a laterally projecting knob and the associated wall of the carrier being provided with a slot through which the slide plate is connected with said knob. 

